April 04, 2012

It's just a matter of time before a major earthquake strikes Southern California, no question about it. Everyone knows this will happen, from the geologists and scientists at the USGS, to the journalists, our political officials, and everyone else in between. Spreading the message to the public and having them take action remains the biggest challenge. Not knowing when or where exactly this quake will hit is what keeps people from taking the necessary measures to prepare. And no one can really blame them, the ability to predict earthquakes is still in the works and knowing the exact location of where the epicenter will be can be elusive.

Fault Lines We Know, And Don't Know About

Take a look at the USGS's map of Southern California and you will see about dozens or more red lines running along the state that mark where faults are. Most of these fault lines are active and quite dangerous such as the San Andreas Fault because they can cause powerful earthquakes. But, just think about the faults that scientists haven't discovered yet -- the ones so deep or so out of our radar that could very well be the ones that could cause the "Big One."

A recent article published by the Natural Hazards Center in Boulder Colorado highlighted the danger that unknown or unmapped faults (also known as "blind" faults) pose to cities and towns in earthquake prone areas. The author, Erol Kalkan, detailed the events that led to the destructive 6.1 earthquake in Christchurch, New Zealand back in February 2011.That earthquake was the deadliest that the country had seen in 80 years.

According to Kalkan, 5 months before the earthquake in Christchurch occurred, a 7.1 magnitude earthquake struck some 20 miles west from the city, in the small town of Darfield. Scientist believe that the earthquake in Christchurch was one big aftershock from the Darfield earthquake. And get this: both of those earthquakes occurred in a previously unmapped fault line.

Last year, another earthquake struck in a previously unmapped fault: the one last August in Mineral, Virginia which caused alarm along the East Coast and damaged the Washington Monument. And back in January 2010, the 7.0 magnitude earthquake in Haiti was also generated by an unmapped fault.

Kalkan explained that scientist are constantly searching for new faults by using laser imaging technology. Californian geologists have used this technology as well, but the work continues. There are still faults out there that need to be mapped so that they can be monitored by scientists.

(Photo: Aerial view of the San Andreas fault from 8500 feet altitude)

The Most Well-Known Fault in California

There are certainly many faults that still need to be identified, but why not take the time to write about the most well-known fault in the state, and probably the world: the San Andreas Fault. The San Andreas Fault is the longest fault in California. It runs 850 miles from the southern to the northern part of the state. It begins in Bombay Beach, on the Salton Sea some 168 miles south east of downtown Los Angeles, and it goes up north ending at the Mendocino Triple Junction, about 279 miles north of San Francisco, on the coast.

This deadly fault is responsible for most high profiles earthquakes that California has experienced, beginning with the most deadly earthquake in American history: the 1906 San Francisco earthquake, which measured between 7.7 to 8.25 magnitude. The Loma Prieta Earthquake in San Francisco in 1989 also occurred along the San Andreas Fault, it measured 6.9 in magnitude.

(Photo: A crushed car after the 1989 Loma Prieta Earthquake in San Francisco.)

Another well-known area along the San Andreas Fault is Parkfield, in the central part of the state. Parkfield is the most monitored area of the world for earthquake activity, here is where a major earthquake strikes an average of every 22 years; a 6.0 magnitude quake struck there in 2004."The Parkfield Experiment" is a USGS program in Parkfield that is helping scientists understand how earthquakes work and how faults behave.

So Did The San Andreas Fault Cause The Northridge and Whittier Earthquakes?

Nope. The San Andreas fault did not cause the Northridge earthquake back in 1994. That earthquake occurred in a previously unmapped fault, now known as the Pico Thrust Fault.The 1989 Whittier earthquake, which caused a lot of damage in East Los Angeles also occurred on a previously unknown fault. So, I hope you're beginning to see a pattern here -- big quakes have happened where no one expected them happen.

Many USGS scientist are predicting that the Big One may happen along the San Andreas fault -- more specifically, with an epicenter in the Salton Sea, where the fault originates. There is a lot of focus and attention placed on this prediction, which is justified. At the same time, the pattern of earthquakes that have been created by unmapped or blind faults is quite alarming and more needs to be done to identify potential hot spots for new earthquakes.

The earthquake in Darfield, New Zealand happened on a fault that led to the city of Christchurch. The two cities were connected by this fault, so when one big earthquake struck the smallest of them, no one paid that much attention. But the aftershock created by that quake did get the world's attention, and by then it was too late.

The lesson learned from Christchurch, New Zealand is to pay closer attention to those bigger quakes that tend to happen in more remote or far areas because you never know if that earthquake just happened on an unmapped fault that runs right beneath your home.

As always, preparedness is key. Store that water and food and stay safe.

March 20, 2012

All is calm in Southern California after the earthquake in southwestern Mexico on Tuesday. There hasn't been any major earthquake activity for a while in SoCal, except for the two March 14 small quakes in Ocotillo Wells, which measured 3.3 and 3.4 magnitude and were just over 10 miles deep.

Still, I believe Californians should be vigilant after a quake of the size in Mexico struck south of the border. Some would say that quake was too far away to have any effects on our faults, but indeed, the earth is one and we do live in earthquake prone zones.

I have been living in Tokyo almost 2 years now, but I daily monitor the quake activity in the SoCal region because it's important to look for patterns. Back in 2010, a huge quake hit Haiti, then a month later one hit down in Chile, and so on. Do some quakes trigger others? We can't say for sure, but when they occur, they come in batches.

We are also experiencing a period of extensive solar activity and flares, I wrote an article about it a couple last November. Some scientist believe that this solar activity has an effect on the Earth's electromagnetic field and a couple of studies that found a correlation between quakes and solar explosions.

The eastern shore of Japan had at least 5 earthquakes between 5 and 7 magnitude last week, this happened shortly after the solar flares that were making headlines just a week before. Coincidence? I don't think so.

We may not all be scientist or seismologists, I'm just a journalist, but I do believe that our faults run deep and shallow and they are quite extensive, and as long as you live in a country on the Pacific Ring of Fire (like Japan and the West Coast of the U.S.) you should know that an earthquake may be around the corner at any time. So, prepare yourself and your family; replenish that bottled water and your emergency food supply, have those flashlights handy, and be safe.

February 03, 2012

We all have our different and similar ways to prepare for an emergency and the Los Angeles Earthquake Blog wants to know what you do or have done to ready yourself and your family for a natural disaster where you live (doesn't have to be in Los Angeles). The "Thumbs Up" section will be a new section of the blog where we post your stories and anecdotes about emergency preparedness. Do you store anywater? Do you keep a flashlight and plenty of batteries around? TELL US!

Submission Guidelines:

1. Keep your email to a maximum of 1,500 words. Send us photos if you want too!

2. Keep your email focused about what you are ALREADY doing and maybe something else that you're thinking about -- like buying a generator, etc.

3. Write in the subject line: "Thumbs Us Submission," and send your preparedness stories to LAEarthquakeBlog@gmail.com.

Please let me know if you would like your name to be published or not.

November 07, 2011

Greetings my readers, I'm back in Los Angeles for a few weeks before returning to Japan. Even though I'll be in Tokyo, I will continue to write about earthquake activity here in Los Angeles, as well as general emergency preparedness.

This year has brought us powerful earthquakes like those in New Zealand and in Japan. It's not unusual to have strong earthquakes every year, and countries like Japan and New Zealand sit on the Pacific Ring of Fire where frequent seismic activity occurs. But this year we've also had some very unusual seismic activity in the United States, very far from the ring of fire.

In Mineral, Virginia a 5.9 magnitude quake struck on August 23. The quake shook many parts of the East Coast including New York and Washington, DC -- all the way to Canada. It took everyone by surprise and it made headlines around the world. Though there are old faults beneath the area where the quake's epicenter was, no one really was expecting activity that strong.

This week we've had the unusual earthquakes in Oklahoma too. A 5.2 and 5.6 magnitude shook eastern Oklahoma, followed by a dozen of aftershocks. This unusually high seismic activity even has geologists from the USGS scratching their heads.

The Sun

I've been reading a lot about the link of earthquake activity and solar flares. This year, the sun has been quite active and it'll remain so until 2013. Some scientist insist that there is a correlation between earthquakes and powerful solar flares -- that when one of this flares explodes, an earthquake on Earth usually follows. Even Harvard is looking into this: http://adsabs.harvard.edu/abs/2007AGUSMIN33A..03J

Could powerful solar flares help predict earthquakes? My guess is no. An earthquake may indeed happen, but figuring out where is the problem.

Many believe that the sun's activity does have an effect on the Earth's electromagnetic field. According to a USGS page:

Electromagnetic variations have been observed after earthquakes for many years now, but What is less clear is whether or not there are detectable electro-magnetic precursors to earthquakes.

Can it be that the sun's influence on our planet's magnetism is the precursor?

What we know for sure is that when the sun produces such strong flares, it can disturb communications on earth. Those satellites floating on the atmosphere are vulnerable to radiation and problems can happen. Some people would go as far as create doomsday scenerios of what would happen if a powerful solar flare explodes when facing the direction of Earth, but we really don't need mass hysteria.

Earthquakes influenced by the sun or not, it's important to know that Mother Nature can be unpredictable. Here in Southern California we don't know when a quake will hit, and most of us live our lives as if it will never happen. "Ignorance is bliss," right? But, living everyday ignoring the fact that there are dozens of active faults beneath us, is dangerous.

If you haven't prepared your earthquake bag, stored water and food, and created an emergency plan for you and your family yet, get to it. Here is a good resource to get you started: ReadyLA.org

As always, I hope you enjoy this blog. It's reader supported, so please donate if you can. Until next time, please be and stay safe.